<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 4.3.2 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2009, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * Output Class
 *
 * Responsible for sending final output to browser
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Output
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/output.html
 */
class CI_Output {

  var $final_output;
  var $cache_expiration	= 0;
  var $headers 			= array();
  var $enable_profiler 	= FALSE;


  function CI_Output() {
    log_message('debug', "Output Class Initialized");
  }

  // --------------------------------------------------------------------

  /**
   * Get Output
   *
   * Returns the current output string
   *
   * @access	public
   * @return	string
   */
  function get_output() {
    return $this->final_output;
  }

  // --------------------------------------------------------------------

  /**
   * Set Output
   *
   * Sets the output string
   *
   * @access	public
   * @param	string
   * @return	void
   */
  function set_output($output) {
    $this->final_output = $output;
  }

  // --------------------------------------------------------------------

  /**
   * Append Output
   *
   * Appends data onto the output string
   *
   * @access	public
   * @param	string
   * @return	void
   */
  function append_output($output) {
    if ($this->final_output == '') {
      $this->final_output = $output;
    }
    else {
      $this->final_output .= $output;
    }
  }

  // --------------------------------------------------------------------

  /**
   * Set Header
   *
   * Lets you set a server header which will be outputted with the final display.
   *
   * Note:  If a file is cached, headers will not be sent.  We need to figure out
   * how to permit header data to be saved with the cache data...
   *
   * @access	public
   * @param	string
   * @return	void
   */
  function set_header($header, $replace = TRUE) {
    $this->headers[] = array($header, $replace);
  }

  // --------------------------------------------------------------------

  /**
   * Set HTTP Status Header
   * moved to Common procedural functions in 1.7.2
   *
   * @access	public
   * @param	int 	the status code
   * @param	string
   * @return	void
   */
  function set_status_header($code = '200', $text = '') {
    set_status_header($code, $text);
  }

  // --------------------------------------------------------------------

  /**
   * Enable/disable Profiler
   *
   * @access	public
   * @param	bool
   * @return	void
   */
  function enable_profiler($val = TRUE) {
    $this->enable_profiler = (is_bool($val)) ? $val : TRUE;
  }

  // --------------------------------------------------------------------

  /**
   * Set Cache
   *
   * @access	public
   * @param	integer
   * @return	void
   */
  function cache($time) {
    $this->cache_expiration = ( ! is_numeric($time)) ? 0 : $time;
  }

  // --------------------------------------------------------------------

  /**
   * Display Output
   *
   * All "view" data is automatically put into this variable by the controller class:
   *
   * $this->final_output
   *
   * This function sends the finalized output data to the browser along
   * with any server headers and profile data.  It also stops the
   * benchmark timer so the page rendering speed and memory usage can be shown.
   *
   * @access	public
   * @return	mixed
   */
  function _display($output = '') {
  // Note:  We use globals because we can't use $CI =& get_instance()
  // since this function is sometimes called by the caching mechanism,
  // which happens before the CI super object is available.
    global $BM, $CFG;

    // --------------------------------------------------------------------

    // Set the output data
    if ($output == '') {
      $output =& $this->final_output;
    }

    // --------------------------------------------------------------------

    // Do we need to write a cache file?
    if ($this->cache_expiration > 0) {
      $this->_write_cache($output);
    }

    // --------------------------------------------------------------------

    // Parse out the elapsed time and memory usage,
    // then swap the pseudo-variables with the data

    $elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');
    $output = str_replace('{elapsed_time}', $elapsed, $output);

    $memory	 = ( ! function_exists('memory_get_usage')) ? '0' : round(memory_get_usage()/1024/1024, 2).'MB';
    $output = str_replace('{memory_usage}', $memory, $output);

    // --------------------------------------------------------------------

    // Is compression requested?
    if ($CFG->item('compress_output') === TRUE) {
      if (extension_loaded('zlib')) {
        if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) AND strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE) {
          ob_start('ob_gzhandler');
        }
      }
    }

    // --------------------------------------------------------------------

    // Are there any server headers to send?
    if (count($this->headers) > 0) {
      foreach ($this->headers as $header) {
        @header($header[0], $header[1]);
      }
    }

    // --------------------------------------------------------------------

    // Does the get_instance() function exist?
    // If not we know we are dealing with a cache file so we'll
    // simply echo out the data and exit.
    if ( ! function_exists('get_instance')) {
      echo $output;
      log_message('debug', "Final output sent to browser");
      log_message('debug', "Total execution time: ".$elapsed);
      return TRUE;
    }

    // --------------------------------------------------------------------

    // Grab the super object.  We'll need it in a moment...
    $CI =& get_instance();

    // Do we need to generate profile data?
    // If so, load the Profile class and run it.
    if ($this->enable_profiler == TRUE) {
      $CI->load->library('profiler');

      // If the output data contains closing </body> and </html> tags
      // we will remove them and add them back after we insert the profile data
      if (preg_match("|</body>.*?</html>|is", $output)) {
        $output  = preg_replace("|</body>.*?</html>|is", '', $output);
        $output .= $CI->profiler->run();
        $output .= '</body></html>';
      }
      else {
        $output .= $CI->profiler->run();
      }
    }

    // --------------------------------------------------------------------

    // Does the controller contain a function named _output()?
    // If so send the output there.  Otherwise, echo it.
    if (method_exists($CI, '_output')) {
      $CI->_output($output);
    }
    else {
      echo $output;  // Send it to the browser!
    }

    log_message('debug', "Final output sent to browser");
    log_message('debug', "Total execution time: ".$elapsed);
  }

  // --------------------------------------------------------------------

  /**
   * Write a Cache File
   *
   * @access	public
   * @return	void
   */
  function _write_cache($output) {
    $CI =& get_instance();
    $path = $CI->config->item('cache_path');

    $cache_path = ($path == '') ? BASEPATH.'cache/' : $path;

    if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path)) {
      return;
    }

    $uri =	$CI->config->item('base_url').
        $CI->config->item('index_page').
        $CI->uri->uri_string();

    $cache_path .= md5($uri);

    if ( ! $fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE)) {
      log_message('error', "Unable to write cache file: ".$cache_path);
      return;
    }

    $expire = time() + ($this->cache_expiration * 60);

    if (flock($fp, LOCK_EX)) {
      fwrite($fp, $expire.'TS--->'.$output);
      flock($fp, LOCK_UN);
    }
    else {
      log_message('error', "Unable to secure a file lock for file at: ".$cache_path);
      return;
    }
    fclose($fp);
    @chmod($cache_path, DIR_WRITE_MODE);

    log_message('debug', "Cache file written: ".$cache_path);
  }

  // --------------------------------------------------------------------

  /**
   * Update/serve a cached file
   *
   * @access	public
   * @return	void
   */
  function _display_cache(&$CFG, &$URI) {
    $cache_path = ($CFG->item('cache_path') == '') ? BASEPATH.'cache/' : $CFG->item('cache_path');

    if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path)) {
      return FALSE;
    }

    // Build the file path.  The file name is an MD5 hash of the full URI
    $uri =	$CFG->item('base_url').
        $CFG->item('index_page').
        $URI->uri_string;

    $filepath = $cache_path.md5($uri);

    if ( ! @file_exists($filepath)) {
      return FALSE;
    }

    if ( ! $fp = @fopen($filepath, FOPEN_READ)) {
      return FALSE;
    }

    flock($fp, LOCK_SH);

    $cache = '';
    if (filesize($filepath) > 0) {
      $cache = fread($fp, filesize($filepath));
    }

    flock($fp, LOCK_UN);
    fclose($fp);

    // Strip out the embedded timestamp
    if ( ! preg_match("/(\d+TS--->)/", $cache, $match)) {
      return FALSE;
    }

    // Has the file expired? If so we'll delete it.
    if (time() >= trim(str_replace('TS--->', '', $match['1']))) {
      @unlink($filepath);
      log_message('debug', "Cache file has expired. File deleted");
      return FALSE;
    }

    // Display the cache
    $this->_display(str_replace($match['0'], '', $cache));
    log_message('debug', "Cache file is current. Sending it to browser.");
    return TRUE;
  }


}
// END Output Class

/* End of file Output.php */
/* Location: ./system/libraries/Output.php */